au runs terriable when warm/hot

[matty au]

hi guys ,going to work yesterday about 20 mins into the drive and the car starts to lose all power /reluctant to go,i bring it to a standstill and its still idling but just wont rev beyong say 1500 rpm.turn the car off for 5 mins and then i get another 3/4 mins of good driving out of it then starts to play up again,so switch it off and sit for 5 mins and then off i go again for another 3 mins driving,its like something needs to cool down and then its fine for awhile,it heats up and then car runs **** again,what the hell is going on ,would it be a coilpack??????????????????????